I was under the impression that Blackberrys run independently of any particular phone company (in terms of the blackberry email functions, not the phone functions). I have been using a Cingular 8700 for a year in a system that later committed to Nextel. Things worked fine, but so far I cannot switch my email over to an 8800 with the same activation code. I have not heard anything specific from an administrator yet.

More importantly, I got my wife a Cingular 8100 using the same full data plan I have been using on my blackberry. She was told she has to get a T-mobile phone or the blackberry functions will not work. Is this correct? Can the BES administrator control phone plans, or only blackberry exchange functions?